Medical sources at the Kamal Adwan hospital in Bait Lahya in northern Gaza told Aljazeera.net that the six child victims of Tuesday's shelling were from one family.

The Israeli army commander in north Gaza expressed regret "if civilians were indeed hurt".

Aljazeera's correspondent in Gaza City, Wael al-Dahduh, reported that an eighth Palestinian was killed and another two wounded after being shot by Israeli forces stationed east of al-Zaytun neighbourhood in southeast Gaza.

Witnesses reported an exchange of fire in the area between resistance fighters and Israeli soldiers.

Abbas angered

From New York, UN Secretary-General Kofi Annan said he was gravely concerned about Tuesday's Israeli military operations in the northern Gaza Strip.

Six of the victims of the Israelishelling were from one family

"He is particularly disturbed that at least five of the victims were under the age of 18," Annan's spokesman said, adding that the Israeli assault followed a "marked increase" in rocket attacks by Palestinian fighters.

For his part, front-runner in the race for Palestinian president and chairman of the PLO executive committee, Mahmud Abbas, for the first time called Israel "the Zionist enemy" after word of the Bait Lahya killings reached him.

"We are praying for the souls of our martyrs who fell today to the shells of the Zionist enemy," Abbas told a rally in the south Gaza refugee camp of Khan Yunus, a resistance stronghold.

This in turn brought the following rejoinder from Israel's Vice-Premier Ehud Olmert: "Without a doubt, what Abu Mazin said was intolerable and unacceptable, and it cannot serve as a basis for any future cooperation."

Violence decried

Abbas later tried to visit the wounded in a Bait Lahya hospital but drove away without getting out of his car because of tank bursts nearby after a rocket volley by resistance fighters into Israel, which caused no casualties.

"This will not bring peace for anyone. If such aggression continues we will not be able to engage in a peace process," Abbas said, referring to the killing of the youths.

"But I also condemn all pointless [mortar and rocket] actions happening here and there," he said. "These actions are wrong and I will not apologise for [saying] that."

Palestinian officials said Israeli military operations in Gaza threatened to disrupt the election while Israel says it is trying to stop intensifying mortar and rocket fire by fighters who have spurned Abbas's call for restraint.

Victims identified

Referring to the seven killed in the Bait Lahya farm, Aljazeera's al-Dahduh said they had all been identified. Three were brothers who belonged to the Ghaban family.

The other victims were a nephew and two relatives of the Ghaban family besides a member of the Kasih family.

Those injured in the shelling were local residents. They received treatment at Dar al-Shifa hospital in Gaza City.

Farm targeted

The Israeli army initially said it had fired at a group of Palestinians who were seen firing rockets, but the targeted area was an agricultural farm that was visible from the Israeli military posts guarding Jewish settlements.